Palpostilpnus ngoclinhensis Pham, Sheng, Park, Tran & Reshchikov, sp. nov.

(Figures 2E, 11)

Material examined. Holotype: ♂ (IEBR), VIETNAM, Kon Tum Province, Ngoc Linh Nature Reserve, 15°05.174’N 107°51.522’E, 1,800 m a.s.l., 7 March 2019, sweep net, Pham V.P. coll. Paratype: 1♂ (IEBR), similar locality and collector as holotype, 15°05.640’N 107°50.740’E, 1,661 m a.s.l., 8 March 2019.

Diagnosis. Black body; occipital carina dorsally broadly absent; postero-ocellar distance equal to ocular-ocellar distance; combined area superomedia and area petiolaris of propodeum open anteriorly; area postero-externa incomplete; T1 stout, 1.5× as long as apical width.

Description of holotype. Face 1.2× as wide as high, granulose, with setae, centrally weakly convex. Clypeal suture indistinct. Clypeus 1.7× as wide as high, weakly convex, coriaceous, ventral margin round. Mandible moderately stout, distinctly narrow to apex, teeth sharp, upper tooth much broader and slightly longer than lower tooth. Malar space matt, 1.3× as long as mandibular basal width (Fig. 11A). Gena punctate, with setae. Frons and vertex rugose punctate, posterior portion from behind ocelli to occipital carina steeply sloping. Postero-ocellar distance equal to ocular-ocellar distance, 0.9× as long as median ocellus diameter (Fig. 11B). Antenna with 22 flagellomeres. Occipital carina broadly absent dorsally (Fig. 11C).

Mesosoma. Pronotum polished, with sparse punctures dorsally. Epomia present (Fig. 11E). Mesoscutum coriaceous, 1.0× as long as its maximum width. Notaulus absent. Scutellum moderately convex, anterior half with arched wrinkles, posteriorly smooth, lateral carina present basally (Fig. 11F). Mesopleuron punctate, with setae, except polished and impunctate medially; epicnemial carina present on ventral 0.7 of mesopleuron. Sternaulus shortly impressed behind epicnemial carina. Metapleuron moderately sparsely punctate, with setae. Juxtacoxal carina weakly present (Fig. 11E). Propodeum gradually sloping in lateral view, subpolished with sparse punctures. Combined area superomedia and area petiolaris of propodeum open anteriorly; area postero-externa incomplete (Fig. 11G). Spiracle small, circular.

Wings. Fore wing length 2.5 mm, vein 1cu-a slightly postfurcal to M&RS, curved ventrally, vein 3rs-m absent, vein 2rs-m about 1.6× length of M between 2rs-m and 2m-cu, length of CU between 1m-cu&M and 2cu-a equal to length of 2cu-a. Hind wing with distal abscissa of CU absent.

Legs. Inner profile of basal portion of fore basitarsus distinctly bent. Hind coxa with distinct punctures. Hind femur 3.9× as long as its maximum width, 0.8× as long as hind tibia length. Hind basitarsus 0.45× as long as tarsus.

Metasoma. T1 1.5× as long as apical width, polished, with punctures latero-posteriorly, dorso-lateral carinae present; petiole flat; postpetiole broad; ventrolateral carina weak; spiracle small, round.T2 onwards densely punctate. T2 moderately long, 1.6× as long as basal width, 0.9× as long as apical width (Fig. 11D).

Colour. Body black. Mandible (except apex) and palpi yellow. Antero-lateral part of mesoscutum and anterodorsally corner of mesopleuron with reddish brown. Fore and mid legs yellow, except mid tarsus brown. Hind leg reddish brown, tibia (except subbasal part) to tarsus black.

Variations. Paratype is similar to the holotype, except the forewing length is 2.6. mm, length of CU between 1m-cu&M and 2cu-a is slightly shorter than length of 2cu-a.

Female. Unknown.

Comparative notes. This new species resembles P. pterodactylus and P. incompletus by the broadly absent occipital carina dorsally and the shorter T1. It can be recognized from these two species by the coloration of body, the absence of combined area of propodeum, and the sculpture of scutellum.

Etymology. Named derived from its type locality, Ngoc Linh Nature Reserve, Kon Tum Province.

Distribution. Currently known only from montane evergreen forest at Ngoc Linh Nature Reserve, Kon Tum Province, Vietnam.